The lens covering says to only use a 15w replacement bulb and all the replacement bulbs are 10w. Why?
Answer Hello Elka. You can go smaller, but not larger. The manufacturer does a 10W bulb for the unit.
my exterior light keeps shorting out.
Answer Mark, Are you sure the cavity light isn't being used as a "night light", or left on for extended periods of time. The 120 VAC 10 watt light bulb is not designed for extended periods of use, and will "burn out" in minimal amounts of time. Otherwise, You'll need to check the blue/black, and white wires from the door hinge to the dispenser light switch and from the switch to the light socket, yellow/black wire, for frayed wires and loose connections.